"Unknown warning option" build failure(s) — clang 3.4

PackageVersionSupposed error messageFull log Bug report
booth 0.1.0-1error: unknown warning option '-Wunsigned-char' [-Werror,-Wunknown-warning-option] Log
byzanz 0.3.0+git20130319-2error: unknown warning option '-Wunsafe-loop-optimizations'; did you mean '-Wout-of-line-declaration'? [-Werror,-Wunknown-warning-option] Log
clutter-gesture 0.0.2.1-7error: unknown warning option '-Werror=unused-but-set-variable'; did you mean '-Werror=unused-const-variable'? [-Werror,-Wunknown-warning-option] Log
freebsd-glue 0.2.13error: unknown warning option '-Werror=maybe-uninitialized'; did you mean '-Werror=uninitialized'? [-Werror,-Wunknown-warning-option] Log
libldm 0.2.3-2error: unknown warning option '-Wno-unused-local-typedefs' [-Werror,-Wunknown-warning-option] Log
libmbim 1.6.0-2error: unknown warning option '-Wunused-but-set-variable'; did you mean '-Wunused-const-variable'? [-Werror,-Wunknown-warning-option] Log
libqmi 1.4.0-1error: unknown warning option '-Wunused-but-set-variable'; did you mean '-Wunused-const-variable'? [-Werror,-Wunknown-warning-option] Log
mg 20110905-1.1error: unknown warning option '-Werror=unused-but-set-variable'; did you mean '-Werror=unused-const-variable'? [-Werror,-Wunknown-warning-option] Log
network-manager-openvpn 0.9.8.4-1error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option] Log
network-manager-pptp 0.9.8.4-1error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option] Log
network-manager-vpnc 0.9.8.6-1error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option] Log
qtwebkit 2.2.1-7error: unknown warning option '-Werror=unused-local-typedefs' [-Werror,-Wunknown-warning-option] Log
xlog 2.0.11-1error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option] Log

13 errors